Why does it only have to be a yes or no question. There are many other factors that need to be looked by you Bhai Sahib. Niddar Singh ji apologized for the many mistakes he has made in the book. After watching the video and how speachless he was on his views, I don't think I'll buy the book. Books about Sikhi with mistakes in them seem to dilute peoples minds and call Gurmat follow Sikhs fanatics and so on.
Have you read the book?
If you haven't you are in no position to make any criticism.